JMK 2 Build System

JMK2 is a rewrite of the JMK build system. I am slowly porting Bluejay to JMK2 instead of the legacy M4-based JMK build system.

JMK2 is used to generate makefiles for each project in Bluejay. A project is a directory with a Jmk2 file (case sensitive). Each project produces a single output based on some sources.

The script bin/jmk2 looks in the source tree for Jmk2 files, and process each one into the corresponding Makefile. It accepts option definitions with the -D flag, eg ./bin/jmk2 -DSOME_OPTION=123. You can also specify the C compiler, assembler, and linker to use with the -c, -a, and -l flags, respectively.

Here is an example Jmk2 file:

init hello # hello is the name of the project
srcs hello.c world.c # the source files this project uses
type executable # the preset type of project this is

Each line consists of a command (init, srcs, type) and its arguments. The commands are documented here:

init name [target]

Initializes the project with a given name. The name is currently unused, but should be set to a descriptive identifier.

target is the name of the target that the project generates. By default it is the same as name. For an executable, this could be hello or hello.exe. For a shared library, libhello.so, etc.

preset preset_name

Applies the preset preset_name. A preset is a function defined in the ::presets namespace which makes some changes to the project state.

These are the default presets:

  • freestanding Changes the cflags to build a freestanding binary (without linking the standard library).

  • optimize Changes the cflags and asmflags to enable compile-time optimizations.

  • 32 Tells the compilers to produce a 32 bit build.

  • debug Tells the compilers to enable debug information in the resulting builds (enables DWARF symbols).

  • warn Enables useful warnings and -Werror.

  • nasm Sets nasm as the default assembler.

presets preset_a [preset_b]...

Applies all the given presets in order. Identical to calling preset once for each argument.

cflag string

Adds string to the ::cflags variable, which will be passed to the C compiler.

cflags string_a [string_b]...

Adds multiple strings to the ::cflags variable, the same as calling cflags repeatedly.

asmflag, asmflags

Same as cflag, cflags but for the ::asmflags variable.

option name default_value

If the option name has not been specified when invoking bin/jmk2, sets the value of the option to default_value. Options can be read with ::options(option_name).

TODO: finish!